The present invention relates to an assembly of an ECG monitoring device including medical electrodes of a known, and accepted design used to detect bio-skin potential, and more particularly said invention to such a monitoring device designed to be easily and economically constructed. This arrangement is particularly useful in operating room and recover room patient ECG monitoring applications.
A number of arrangements for disposable medical electrodes per se for patient ECG monitoring are known in the prior art, as are automated methods of assembly, a general form being shown in U.S. Pat. No. 3,805,769, which is incorporated herein by reference. Typically such medical electrodes comprise a metal conductive member fixed to a foamed plastic or microporous base sheet. In use these sheets are applied to the skin with the aid of a pressure sensitive adhesive surrounding the conductor member, the resilience or flexibility of the sheet cooperating with the adhesive to hold the electrode firmly against the skin. The electrode conductive element is commonly positioned away from the skin to minimize motion artifacts or noise by including a pre-gelled pad overlying the conductive element. The pad and base section are covered by a protective member to be removed prior to use. In addition to the above-noted design for the individual electrode members, there has been developed in the art various types of composite monitoring devices, known as "back pads". These devices normally include a base or substrate with a number of monitoring electrodes mounted thereon. To the best of Applicant's knowledge, these designs employ electrode assemblies that must be meticulously assembled to the base substrate, as they are not capable of manufacture by automated production methods, such as the general type disclosed in said U.S. Pat. No. 3,805,769. As an additional matter, the designs in existence prior to the present invention were not pre-gelled, to the best of Applicant's knowledge.
Briefly, an ECG monitoring device constructed in accordance with the present invention comprises a first or bottom resilient foam or sponge-like sheet and a second or top resilient foam or sponge-like sheet adhesively attached thereto to provide a base substrate to which a plurality of electrode packages are affixed. The top or upper sheet includes a plurality of openings formed therethrough to receive the terminal portions of the medical electrodes for attachment of lead wires thereto.
Each electrode package includes an electrode structure and a cover means, said electrode comprises an adhesively coated base layer, with a terminal or conductive connector assembly engaged on opposite sides thereof, preferably in the form of a snap fastener. A pre-gelled pad is engaged over the connection assembly on the adhesively coated side of the base layer. The cover structure which is removable overlies both said adhesively coated surface and said pad to protect and preserve the integerity of the adhesive and gel electrolyte. The electrode packages are mounted to the base substrate in overlying relation to said openings by a second adhesive layer applied to the opposite side thereof. In this assembled position, a portion of the terminal or connector assembly of each electrode extends from the side of the base layers opposite of said pad, and is aligned with one of said openings. A plurality of lead wires are provided and connected, one to each said conductive terminal assembly. Said lead wires are disposed intermediate the respective sheets and extend from an edge of the device. Preferably, the distal ends of said wires are assembled to a conventional, plug-in type of connector assembly for connecting the device to monitoring apparatus.
With the present invention, it is possible to provide an ECG device of the general type discussed above wherein the individual electrode members are of a known and accepted design, an extremely important factor in light of the passage into law of medical device legislation. Further, these electrode structures are embodied in pre-gelled electrode packages which are manufactured to finish a construction by automated production methods, as alluded to previously. Accordingly, all that need be done is to mount the electrodes to a substrate and connect the lead wires thereto. As can be appreciated, the present design materially reduces the cost of the final product.
Other objects and advantages of the present invention will become apparent from the following detailed description when taken together with the accompanying drawings wherein like numerals are used throughout to designate similar parts and components.